Introduction, RM

Introduction

            Ocean acidification is occurs as the pH of the ocean ecosystem decreases. The primary cause of the acidification is deposition of carbon dioxide from the Earth’s atmosphere. Atmospheric carbon dioxide deposition is one of the most preventable causes of ocean acidification due to the fact that it is almost entirely caused by humans. Acidic ocean waters are detrimental to the marine ecosystem. The acidic waters break down calcium carbonate in the ocean waters that primarily exists in corals and shells of marine animals. The breakdown of calcium carbonate will kill these animals, destroying the marine food web from the base up. Prevention of ocean acidification through atmospheric carbon dioxide is absolutely critical in order to keep the oceans of the world in the pristine condition they exist in today.

Graphic of Solution, RM

Carbon Dioxide Capture Tower as sketched by RM

Solutions Document, JA

Solutions

            Since direct absorption of carbon dioxide is the primary cause of ocean acidification, reducing the amount of CO₂ in the atmosphere would have the greatest effect of reduction of it. A large-scale solution is the use of CO₂ scrubbers, towers that absorb CO₂ from the air. Air with CO₂ enters a first tower that contains gaseous solvents, usually ammonia, and is cooled. The ammonia absorbs the CO₂ from the air, thereby isolating it. The remaining air is now cleaner and returned to the atmosphere. The cooled CO₂ is moved to another tower or another chamber and is heated. The CO₂ and ammonia separate and the CO₂ is drawn out and pumped into storage containers. The ammonia is recycled back to the first tower to be used again. This process is relatively new and is still being trialed and tested, but it has great potential. Currently, it costs $150 to remove one ton of CO₂ using carbon scrubbing, which would add 4-9 cents/kilowatt to an individual’s energy bill. In time, this cost is sure to come down as technology improves. The towers would be placed on factories or power plants, where much of the CO₂ is produced. The CO₂ that has been removed from the air can be used for useful purposes. The gas can be pumped underground into almost depleted oil reserves. The CO₂ helps dislodge the oil so that all of it can be extracted from the ground. Carbon scrubbing can remove 80-90% of released CO₂ from the atmosphere.

            A second solution is the addition of calcium carbonate to coastal waters. This solution more directly solves ocean acidification. Calcium carbonate is the mineral that marine organisms such as coral, crabs, and shellfish use to make their exoskeletons. Ocean acidification inhibits their ability to use calcium carbonate to do so. By adding extra calcium carbonate to the water, it can offset the increased CO₂ and balance marine ecosystems. The extra calcium carbonate absorbs the CO₂ so that organisms can use the natural amounts for exoskeleton growth. This solution would be most effective in coastal regions where ocean acidification is highest and where the added calcium carbonate could be most effective. The addition of this mineral may be a concern for environmentalists and tourists visiting the area. They may not be too keen on adding more to the ocean. 

Graphic of Causes, EN

Causes Document, JA

Causes

There are a number of causes of ocean acidification. The primary cause is the direct absorption of Carbon Dioxide (CO₂) into ocean water. CO₂ emissions are mostly manmade. Fossil fuel consumption added 5637.9 teragrams of CO₂ to the atmosphere in 2006.  Although steel, iron, and cement industries add hundreds of teragrams per year, burning fossil fuels is the number one cause. When CO₂ is in the air, water can absorb it. Through chemical processes, carbonic acid is formed which increases the acidity of the ocean. With fossil fuel usage increasing every year, the acidification will only get worse.

            Acid rain is a secondary cause of ocean acidification. Burning fossil fuels, farming, and raising livestock create sulfur dioxide, ammonia, and nitrogen oxide. These gases rise into the atmosphere and then return to Earth in precipitation, forming nitric and sulfuric acid. This is called acid rain. The rain falls on land and in the ocean. Acid rain mainly affects coastal water areas, where tourism is centered and people live. Acid rain that falls on land can work its way into other bodies of water, such as rivers and streams, and flow into the ocean.

            Deforestation is another secondary cause of ocean acidification that is linked to CO₂ production. Trees and other plants use CO₂ in photosynthesis to live and produce oxygen.  The removal of CO₂ by agriculture and forestry is called carbon sequestration. Deforestation decreases the amount of trees that can remove CO_2­, thereby increasing CO₂ content. A single acre of trees can remove 4 tons of CO₂ from the atmosphere per year. This may not seem like a lot, but a large, undisturbed forest with thousands of acres can have a noticeable effect.

Research Document, EN

What is the CO2 problem?

Ocean Acidification

·       The lowering of the ocean’s pH levels due to the absorption of carbon dioxide in the atmosphere

·       Excess amounts of CO2 are changing the chemistry of the water and disrupting many forms of sea life

·       A more acidic ocean could wipe out species, disrupt the food web and impact fishing, tourism and any other ocean related activity

·       About  500 million use the coral reefs for daily food and income

·       The great barrier reef creates about $6.5 billion dollars each year from tourism alone

·       Since the time of the industrial revolution, the ocean has dropped 0.1 units in the pH scale

·       Over the last 250 years the oceans have 530 billion tons of CO2 creating an 30% increase in ocean acidity

·       In perspective the oceans’ pH has been stable for about 20 million years, and when mankind began burning fossil fuels it dramatically increased

·       Researchers predict that the oceans’ acidity will double by 2100

·       Will most recently affect the polar regions but in the next 39 years it could start to show corrosiveness in the Gulf of Mexico

Effects on Sea Life

·       Is extremely harmful to marine creature with seashells

·       Carbonate is the substance used to form shells for many shellfish in the ocean

·       The more the pH drops the weaker the shells become until they eventually break

·       It does not just apply to the shellfish in the ocean, but the entire chain of the food chain

·       If the small animals die, then the bigger ones do not have any food to eat

·       The loss of the coral reef would prevent some of the absorption for hurricanes and storm surges

·       Corrosiveness of ocean acidification is similar to osteoporosis in bones

·       Coral reefs provide homes to about 25% of all marine life

·       Disappearing coral reefs are already impacting the fishing and tourism industries

·       Disrupting the food chain especially at the most fundamental and smallest levels

·       It is disintegrating the shells of pteropods which are the basic food sources for Pacific juvenile salmon and krill

Natural resources defence council. (2009, September 17). Retrieved from      http://www.nrdc.org/oceans/acidification/

Pmel:carbon program. (n.d.). Retrieved from http://www.pmel.noaa.gov/co2/story/What is Ocean Acidification?

Moyer, R. P. (2009). Retrieved from website: http://soundwaves.usgs.gov/2009/11/

Oceanic Hypoxia: EN Research

Oceanic Hypoxia

-          Occurs when the oxygen concentration in the water falls below 2mg/L, the necessary level to sustain most animal life

Eutrophication

-          The addition of excessive amounts of nitrates and phosphates, which when added to a marine environment causes accelerated stimulated plant and algae growth and depletes the normal amount of oxygen necessary for marine life

-          Creates algae blooms which can be deadly to the surrounding plant and animal life

-          Largest eutrophic zones are located around industrialized areas with tons of water pollution each year

Causes of Eutrophication

-          Point Sources

o   Any single identifiable source of pollution from which pollutants are released such as a sewage pipe from an industrial factory

-          Nonpoint Sources

o   Generally caused by runoff from rain and seepage

o   Fertilizers in a high water table zone

Problems Caused

-          decrease in the population of species in hypoxic areas

-          destruction of coral reef ecosystems

-          leads to dead zones where no life can be sustained

-          damages the economic coastal fishing industry

-          lowers the reproductive hormones in male and female fish in hypoxic environments

Ways to Solve

-          addition of aluminum sulfate in the water to decrease levels of phosphates

-          decreasing the amount of point and nonpoint sources of pollution in coastal industrial areas

-          learning eco friendly habits

Internet Sources

http://www.epa.gov/owow/wetlands/pdf/hypoxia_pr.pdf

http://toxics.usgs.gov/definitions/hypoxia.html

http://oceanservice.noaa.gov/products/pubs_hypox.html

http://www.cop.noaa.gov/stressors/pollution/

http://oceanservice.noaa.gov/facts/deadzone.html

http://kodu.ut.ee/~olli/eutr/html/htmlBook_4.html

http://oceanservice.noaa.gov/education/kits/pollution/03pointsource.html

Oceanic Acidification: JA Research

Acid Rain/Ocean Acidification

·      Caused when carbon dioxide, sulfur, or nitrogen combine with seawater

·      Acidification affects the organisms at the bottom of the food chain

o   Sea urchins, coral, plankton

o   Harder to harness calcium carbonate for exoskeleton

·      Increased nitrogen causes algal growth àalgal blooms and eutrophication (low oxygen)

·      Acid rain has largest effects on coastal waters

·      Fossil fuels, farming, raising livestock all create sulfur dioxide, ammonia, and nitrogen oxidesànitric and sulfuric acids

·      Most affected areas: near power plants, eastern North America, Europe, southern and eastern Asia

·      Ocean pH has been lowered by 0.1 since before Industrial Revolution; predicted to decrease another 0.3-.04 by 2100

Woods Hole Oceanographic Institution (2007, September 7). Acid Rain Has A Disproportionate Impact On Coastal Waters. ScienceDaily. Retrieved March 2, 2012, from http://www.sciencedaily.com­ /releases/2007/09/070907175147.htm

·      Acidification affects coral reefs

o   Slows growth of reefs (they need carbonate)

o   Reefs are very important to marine life

·      Reduce CO2 emissions to slow acidification

Natural Resources Defense Council (2009, September 17). Ocean Acidification: The Other CO2 Problem. Natural Resources Defense Council. Retrieved March 2, 2012, from http://www.nrdc.org/oceans/acidification/default.asp

·      Severe acidification happened before (water was so corrosive it ate the shells of animals)

o   Took millions of years to recover

·      Ocean acidifying 10 times faster than 55 million years ago when there was a mass extinction; acidification was 55 million years ago

·      .1 lowering of pH means that ocean has 30 percent more hydrogen atoms than 200 years ago

·      Tests run in labs show that acidification inhibits ability to grow calcium carbonate shellsàruin whole ecosystems

·      Lots of CO2 released into atmosphere 55 million years ago; Paleocene-Eocene thermal maximum, or PETM

o   Caused many deep ocean species to go extinct

o   Ocean bottom turned red because of acidification

·      Acidification happening faster now than before, so more extinctions possible

·      Acid is stronger, so could affect shallow water too

An Ominous Warning on the
Effects of Ocean Acidification. Yale Environment 360. Retrieved March 7, 2012 from http://e360.yale.edu/feature/an_ominous_warning_on_the__effects_of_ocean_acidification/2241/

Oceanic Acidification: RM Research

Ocean Acidification Caused by Atmospheric Carbon Dioxide

            Atmospheric carbon dioxide affects not only the air quality, but also the pH levels of the ocean below it. Specifically, the carbon dioxide makes the ocean water more acidic, resulting in the effect known as ocean acidification. Ocean acidification is detrimental to marine life. Acidification has the greatest effect on corals and plankton. Ocean acidification is important for humans to know about because human made resources are the primary cause for the abundance of carbon dioxide. The loss of marine resources from ocean acidification affects the marine ecosystem adversely.

            Higher acidic levels in the ocean have a degrading affect on the marine life. Most commonly, ocean acidification affects corals both tropical and sub-tropical. Acidic ocean water attacks the coral’s carbonate structure. The carbonate structure gives the coral its support and protection. Without the carbonate shell, the soft, organic part of the coral is left exposed. The soft part is then subject to predation and natural destruction. The elimination of coral can exterminate tropical and sub-tropical reefs. All of the organisms that inhabited the destroyed coral reef lose all forms of shelter and most food sources. The organism either falls subject to predation or starvation as a result of the destruction of a reef. Plankton are also susceptible to ocean acidification. Acidic water breaks down most plankton’s protective carbonate shells. Without the shells, the plankton die, effectively eradicating the food source of many marine organisms. Ocean acidification also has detrimental affects on nearly every organism inhabiting the oceans.

            Ocean acidification is primarily caused by humans. Humans cause ocean acidification by the combustion of fossil fuels that humans use for daily uses. Most humans are responsible for the combustion through a very common method of transportation. Any gasoline-burning vehicle emits carbon dioxide in gaseous from which travels straight into the atmosphere. Factories also burn off an immense amount of fossil fuels leading to direct atmospheric absorption. The main reason for atmospheric carbon dioxide is an increasing earth population combined with a dependence on the burning of fossil fuels to perform ordinary tasks. Burning fossil fuels is an action that can easily be both avoided and prevented by humans. However, the current increasing rate of combustion and carbon dioxide entering the atmosphere only leads to the prediction that the ocean will continue to get more acidic.

            Ocean acidification has a detrimental effect on the oceans that humans take for granted today. The acidification primarily affects corals and planktons, but can have effects through the entire marine ecosystem. The main cause of ocean acidification is oceanic absorption of atmospheric carbon dioxide. The carbon dioxide is a direct result of the combustion of fossil fuel, which humans are increasingly burning. As fossil fuels are increasingly used, Ocean acidification may destroy the world’s oceans as they are known today.

Works Cited

The Royal Society, Science Policy Section. (2005). Ocean acidification due to increasing atmospheric carbon dioxide. Cardiff: Clyvedon Press Ltd.